Some electrical machinery have slip rings or collector rings mounted on the rotating shaft of the rotor. Electrical brushes which glide on the slip rings transmit electrical current typically exciter currents to the rotating parts of the machinery. Inasmuch as the slip rings or collector rings belong to the rotating parts of the machine, they must be affixed to the rotating shafts in a manner which insures the reliable transmission of the exciter currents to the rotor windings even at high rotor speeds. For this reason, the slip rings must be made from a material having high electrical conductivity, and often the slip rings are made of graphite or a suitable mixture of graphite and metal. These materials do not have the required rigidity and strength to withstand severe mounting forces or stresses which occur during operation. For this reason, it is known to provide graphite slip rings with pressed-in metal parts which can withstand tangential stresses as well as radial stresses that are applied when the slip rings are press fitted on the shaft during construction or centrifugal forces occurring due to imbalance at high speeds of operation. The construction of slip rings with metallic parts is quite expensive. It has been known in the art to mount graphite slip rings on shafts or hubs directly and without intermediate metal parts and to hold them in place through frictional forces or by means of adhesives. However, such bonds are often incapable of withstanding prolonged alternating stresses, especially changing temperatures at high speeds of operation. Such operation generates shear stresses which tend to adversely affect the bond between the slip rings and the shaft. Furthermore, the frictional forces exerted by the brushes also generate tangential stresses which must be absorbed by the bond.